• The Korean Journal of Mycology
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• v.46 no.4
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• pp.359-367
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• 2018

As an effort to explore fungal diversity, fungal survey was undertaken in 2017 in the vicinity of demilitarized zone (DMZ) located in Yeoncheon-gun, Gyeonggi-do, Korea. For the survey, wild plants and soils were sampled and subjected to fungal isolation. A total of 18 genera and 23 species including five unrecorded fungal species, Mortierella sclerotiella, M. sossauensis, M. verticillate, Eupenicillium saturniforme, and Trichoderma hispanicum, were obtained from the survey. This study described their morphological characteristics including colony features formed on media, light microscopic images and molecular characteristics of nucleotide sequences of the internal transcribed spacer (ITS) region, 18S and 28S rDNA, ${\beta}-tubulin$ gene, calmodulin, and translation elongation factor $1{\alpha}$ ($tef1{\alpha}$) nDNA genes.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.65.2-65
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• 2003

To protect the plant against several soil-borne pathogens, we are currently constructing disease-resistant transgenic root stock for the growth of cucurbitaceae vegetable plants, watermelon and gourd. We made a watermelon cDNA library from Cladosporium cucumerinum-Infected leaves for substractive hybriazation and differential screening. We isolated the several pathogen inducible cDNA clones, such as caffeoyl-CoA-methyltransferase, LAA induced protein, receptor-like kinase homolog, hydroxyproline-rich glycoprotein, catalase, calmodulin binding protein, mitochondrial ATPase beta subunit, methyl tRNA synthetase and WRKY transcription factors. We previously obtained CaMADS in pepper and galactinol synthase ( CsGolS) in cucumber that were confirmed to be related with disease-resistance. CaMADS and CsGolS2 were transformed into the inbred line 'GO701-2' gourd, the inbred line '6-2-2' watermelon and the Kong-dye watermelon by Agrobacterium tumerfaciens LBA4404. Plant growth regulators (zeatin, BAP and IAA) were used for shoot regeneration and root induction for optimal condition. Putative transgenic plants were selected in medium containing 100mg/L kanamycin and integration of the CaMADS and CsGO/S2 into the genomic DNA were demonstrated by the PCR analysis. We isolated major soil-borne pathogens, such as Monosporascus cannonballus, Didymella bryoniae, Cladosporium cuvumerinum from the cultivation area of watermelon or root stock, and successfully established artificial inoculation method for each pathogen. This work was supported by a grant from BioGreen 21 program, Rural Development Administration, Republic of Korea.

• Korean Journal of Agricultural Science
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• v.49 no.1
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• pp.113-120
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• 2022

Leaf blight disease caused by Stemphylium species is an important disease in Allium crops, specifically onion, garlic and welsh onion. In 2018, leaf blight symptoms were severe and damaged onion and garlic in Jeonnam province in Korea. In addition, small purple spots on garlic burbs were observed in a post-harvest storage warehouse. Several Stemphylium isolates were isolated from diseased leaves from the field and from garlic bulb samples and were analyzed in terms of homology and the phylogenetic relationship based on the internal transcribed spacer region and calmodulin gene sequence. The results showed that among three Stemphylium species identified, S. vesicarium is most prevalent on onion and garlic. S. eturmiunum was for the first time identified as pathogenic to onion and garlic, whereas S. solani was found in welsh onion crops. Although these isolates grew well at the optimum temperature at 20 - 25℃, they could also grow at low temperatures of 10 - 15℃. A pathogenicity test was conducted using S. vesicarium and S. eturmiunum on onion and garlic respectively. These results showed that two Stemphylium species were highly virulent with cross pathogenicity in onion and garlic. The results of this study can support the biological characterization of Stemphylium species in Korea. Moreover, further research will need to develop fungicide application strategies for onion and garlic crops.

• The Korean Journal of Mycology
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• v.51 no.4
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• pp.383-387
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• 2023

Peanut plants showing mild wilt were found in fields of Iksan, Korea, in August 2021. The diseased peanut plants were collected, and the causal pathogens were isolated using potato dextrose agar (PDA) medium. The isolated IS-1 strain formed white mycelia on PDA, which turned black with age. Sclerotia were produced on the PDA and barley leaves laid on water agar 7 d after incubation at 30℃. The sequences of both the internal transcribed spacer (ITS) region and calmodulin gene of IS-1 showed a 100% similarity with that of Macrophomina phaseolina. A phylogenetic tree constructed using the ITS regions of fungal pathogens causing disease in peanut plants indicated that the IS-1 stain belongs to M. phaseolina. The inoculation of IS-1 sclerotia into peanut seedlings resulted in yellowing and wilt symptoms in aboveground plants and brown to dark rots in roots 35-40 d after inoculation. Overall, the morphological characteristics, molecular identification, and pathogenicity of IS-1 indicate that the causal pathogen is M. phaseolina. This is the first report of charcoal rot caused by M. phaseolina on peanut plants in Korea. Further study is needed to develop the control measures for charcoal rot in peanut plants.

• Journal of Ginseng Research
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• v.48 no.1
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• pp.59-67
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• 2024

Background: Alzheimer's disease (AD) has memory impairment associated with aggregation of amyloid plaques and neurofibrillary tangles in the brain. Although anti-amyloid β (Aβ) protein antibody and chemical drugs can be prescribed in the clinic, they show adverse effects or low effectiveness. Therefore, the development of a new drug is necessarily needed. We focused on the cognitive function of Panax ginseng and tried to find active ingredient(s). We isolated panaxcerol D, a kind of glycosyl glyceride, from the non-saponin fraction of P. ginseng extract. Methods: We explored effects of acute or sub-chronic administration of panaxcerol D on cognitive function in scopolamine- or Aβ_25-35 peptide-treated mice measured by several behavioral tests. After behavioral tests, we tried to unveil the underlying mechanism of panaxcerol D on its cognitive function by Western blotting. Results: We found that pananxcerol D reversed short-term, long-term and object recognition memory impairments. The decreased extracellular signal-regulated kinases (ERK) or Ca²⁺/calmodulin-dependent protein kinase II (CaMKII) in scopolamine-treated mice was normalized by acute administration of panaxcerol D. Glial fibrillary acidic protein (GFAP), caspase 3, NF-kB p65, synaptophysin and brainderived neurotrophic factor (BDNF) expression levels in Aβ_25-35 peptide-treated mice were modulated by sub-chronic administration of panaxcerol D. Conclusion: Pananxcerol D could improve memory impairments caused by cholinergic blockade or Aβ accumulation through increased phosphorylation level of ERK or its anti-inflammatory effect. Thus, panaxcerol D as one of non-saponin compounds could be used as an active ingredient of P. ginseng for improving cognitive function.

• Horticultural Science & Technology
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• v.34 no.4
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• pp.528-536
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• 2016

This study was conducted to examine the effect of 0.4% of $CaCl_2$, $2H_2O$, $1mg{\cdot}L^{-1}$ of Calmodulin (CaM)-SH, 250-folds of coating agent (WE-36), 1,000-folds of $GA_{4+7}+BA$ and 3 types of paper bagging treatments on russet incidence and fruit quality attributes of 'Gamhong' apple. The pattern of russet occurrence was slightly different for 4 years (from 2012 to 2015) in 'Gamhong' apple. The russet occurrence was lowest in $GA_{4+7}+BA$ treatment at 20 days after full bloom (DAFB), compared with other treatments. The $GA_{4+7}+BA$ treatment increased fruit weight at 20 DAFB, while the other fruit quality attributes were not influenced. The russet occurrence was lower not only in a single bag application than in untreated ones but also in yellow bagging and discolored bagging applications than in a white bagging application. The russet occurrence in a bagging application was lower at 20 DAFB than at 30 and 40 DAFB, while fruit quality attributes were not affected by bagging applications. The russet incidence was lower in $GA_{4+7}+BA$ twice treatments at 20 and 30 DAFB, and calcium coated bag at 30 DAFB after $GA_{4+7}+BA$ treatment at 20 DAFB than in untreated fruit. The rate of russet incidence was lowest at equator region in $GA_{4+7}+BA$ treatment, compared with the other fruit regions. Overall, the results suggest that one and/or two applications of $GA_{4+7}+BA$ (1,000-folds) treatment at 20 DAFB should reduce the risk of russet incidence in 'Gamhong' fruit.

• The korean journal of orthodontics
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• v.31 no.1 s.84
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• pp.107-120
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• 2001

Nitric oxide(NO) has been reported to be one of the mediators relating to bone remodelling. Nitric oxide is synthesized from L-arguinine by nitric oxide synthetase(NOS), which is largely divided Into two groups. One group which is composed of $NOS_1\;and\;NOS_3$, is dependent of calcium or calmodulin. The other consisted of $NOS_2$, which is independent of calcium or calmodulin. NOS is thought to be a possible intermediate affecting in the course of tooth movement. This study was designed to evaluate the expression of nitrous oxide synthetase(NOS) in periodontal tissue during the experimental movement of rat incisors, by LSAB(labelled streptavidine biotin) immunohistochemical staining for $NOS_2\;and\;NOS_3$. Twenty seven Sprague-Dawley rats were divided into a control group(3 rats), and 6 experimental groups(24 rats), to which 75g of force was applied, with helical springs across the maxillary incisors. Rats of experimental groups were sacrificed at 12 hours, 1, 4, 7, 14 and 28 days after force application, respectively. After that, the tissues of the control group and experimental groups were studied immunohistochemically. The results were as follows: 1. In control group, the expression of $NOS_3$ was rare in gingiva, dentin, periodontal ligament and alveolar bone, and was mild in the capillaries of pulp and intermaxillary suture. And the expression of $NOS_2$ showed similar pattern to that of $NOS_3$. 2. There were no differences in the expression of $NOS_2\;or\;NOS_3$ in dentin, gingiva, cementum, cementoblast and odontoblast, between control and experimental groups, regardless of the duration of the force application. 3. The expression of $NOS_3$ began to increase at 4 days and showed to the highest degree at 7 days after force application, in the apical region of pressure side of periodontal ligament in experimental groups. 4. The expression of $NOS_3$ in alveolar bone was rare until 7 days, after which it increased to mild degree at 14 days through 28 days in experimental group. But there was no difference between pressure and tension side of periodontal ligament. 5. The expression of $NOS_2$ in periodontal ligament was mild from 7 days after force application, regardless of the side of periodontium, which was generally more evident than that of $NOS_3$. 6. The expression of $NOS_2$ in alveolar bone increased to mild degree at 14 days after force application, and it was evident in osteoblasts, osteoclasts and osteocytes. And the expression of $NOS_2$ was little more stronger in the tension side than that of pressure side of alveolar bone.

• Journal of Life Science
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• v.19 no.4
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• pp.520-525
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• 2009

Early onset of Batten disease (EBD), one of the most lethal neurodegenerative storage disorders of childhood, is caused by inactivating mutations in the Ceroid Lipofuscinosis, Neuronal (CLN1) gene. Neurogranin, a calmodulin-binding protein, is expressed in the brain and participates in the protein kinase C (PKC) signaling pathway. While oxidative stress is the suggested cause of neurodegeneration in EBD, its molecular mechanism(s) remains obscure. In this research, we examined the levels of neurogranin in the brain mRNA of wild-type (WT) mice and EBD knockout (KO) mice, as well as the proteins. We also performed neuronal cultures to measure the expression levels of neurgranin and phosphorylated-neurogranin with or without oxidative stress inducers and anti-oxidants. Results showed that neurogranin in both EBD KO mice brain mRNA and protein extracts decreased in an age dependent manner. However, high amounts of phosphorylated-neurogranin were detected in the 6-month brain. This pattern was also confirmed by cultured neurospheres samples. Moreover, neurospheres treated with $H_2O_2$, an oxidative stress inducer, showed increased phosphorylated-neurogranin patterns. Interestingly, this pattern returned to normal status when treated with N-acetyl-L-cystein, an anti-oxidant, after $H_2O_2$ treatment was performed. Our results suggest that the phosphorylation of neurogranin is affected by oxidative stress status in EBD, and appropriate anti-oxidant treatment will relieve hyper-phosphorylation of neurogranin.

• Journal of Plant Biotechnology
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• v.36 no.1
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• pp.59-63
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• 2009

Calcium ion ($Ca^{2+}$) is thought to play the important role as a second messenger for signal transduction that results in various physiological responses to cope with developmental programs and environmental changes in plant. In plant cells, the central vacuole functions as a major calcium store, which is important for both signal transduction and preventing cytotoxicity. Although there is evidence for the biochemical characterizations of a calmodulin-regulated $Ca^{2+}$-ATPase (ACA11) localized to vacuole membrane, the biological function to ACA11 in plant has not been verified. In this study, we show that the cell death as the hypersensitive response (HR) in mature leaves is induced in transgenic plant of a vacuole ACA-type $Ca^{2+}$-ATPase, ACA11. Evidence that cell death phenotype is the result of ACA11 gene silencing is provided by Western blot assay using membrane fraction proteins extracted from transgenic plant. The 3, 3'-diaminobenzidine (DAB) staining study provides that the cell death is caused by the increase of reactive oxygen species (ROS) in mature leaves of transgenic plants.

• Parasites, Hosts and Diseases
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• v.48 no.4
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• pp.319-324
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• 2010

A family of calcium-dependent protein kinases (CDPKs) is a unique enzyme which plays crucial roles in intracellular calcium signaling in plants, algae, and protozoa. CDPKs of malaria parasites are known to be key regulators for stage-specific cellular responses to calcium, a widespread secondary messenger that controls the progression of the parasite. In our study, we identified a gene encoding Plasmodium vivax CDPK4 (PvCDPK4) and characterized its molecular property and cellular localization. PvCDPK4 was a typical CDPK which had well-conserved N-terminal kinase domain and C-terminal calmodulin-like structure with 4-EF hand motifs for calcium-binding. The recombinant protein of EF hand domain of PvCDPK4 was expressed in Echerichia coli and a 34 kDa product was obtained. Immunofluorescence assay by confocal laser microscopy revealed that the protein was expressed at the mature schizont of P. vivax. The expression of PvCDPK4-EF in schizont suggests that it may participate in the proliferation or egress process in the life cycle of this parasite.